A proposed technique aggregates past probe data with regard to each day of the week and with regard to each time zone and generates statistical data of a travel time that is required from a place of departure to a destination, in order to calculate the travel time with high accuracy. One example of this technique is disclosed in a patent literature JP 2008-241466A. This technique stores traveling time data that relates a traveling time of a moving body such as an automobile with regard to each time zone to information identifying each road and attribute of the day such as the day of the week, in a storage. Every time the moving body travels on an actual road, a travel time required for traveling on the road is measured, and the measured traveling time and the stored traveling time are averaged for adjustment of the stored traveling time. A traveling time until the moving body reaches a point of destination is then predicted, based on the traveling time stored in relation to roads included in a route to the point of destination, the attribute of the day and the time zone.